Broken (self generated variables are banned now) after Scratch 3.0+, you need a time machine to play this. There are no real sprites and no pen. Just variables!
The trick: There are hidden private variables of the "var.script" sprite every 10 pixels (That's 48*36=1728 hidden private variables for the default screen size 480*360). The original variable gets copied into these and shown as the one closest to the mouse pointer / desired (x,y) coordinates.
